A logic analyzer is a test and measurement instrument that is extremely useful for troubleshooting digital circuits involving numerous signals. Like an oscilloscope, a logic analyzer captures signals from a System Under Test (SUT) and displays a representation of those signals on a display screen. Unlike an oscilloscope, which typically has up to four input channels, a logic analyzer may have 32, 64, 128 or more input channels. Oscilloscopes acquire signal data representative of analog characteristics of the signal, such as specific amplitude values, rise times, fall times, etc. A logic analyzer is concerned with logic levels (0 and 1) and timing relationships between the signals.
Data records acquired by a logic analyzer can be very long, for example up to 64 Meg samples on each channel. While the ability to capture such a large amount of data is certainly a desirable feature for a logic analyzer, identifying specific data within a long data record is often a daunting task for a user. For example, a user may need to know how many occurrences (counts) of specific characteristics of digital data have been recorded. Alternatively, users may want to average certain data values, or compute statistics on their data sets using measurement capabilities similar to those in digital oscilloscopes.
Currently, such a user must export digital data sets to an external computer and use a statistical spreadsheet type package (e.g., Microsoft Excel® software), or some custom program, to calculate these counts, averages and other statistics on these data sets. Exporting such large data sets, and then operating on them to produce the desired results is a time consuming process. What is needed is a fast and efficient method and apparatus for producing analog-type measurements, such as, counts, averages, and statistical results, on already-acquired deep memory data records of a logic analyzer.